1. Field of the Invention
The invention relates to a low-pressure process apparatus, and in particular to a low-pressure process apparatus for drying photoresist.
2. Description of the Related Art
FIG. 1a shows a conventional low-pressure process apparatus 10 comprising a base 1, a housing 2, a stage 3, supporting elements 5, actuating devices 6 and an exhaust pipe 7. The stage 3 is disposed on the base 1, supporting a substrate 4. The housing 2 and the base 1 form a chamber 8 receiving the stage 3 and the substrate 4. The exhaust pipe 7 and the supporting elements 5 are disposed on the base 2. The actuating devices 6 are disposed on the base 1. With reference to FIG. 1b, the actuating devices 6 push the supporting elements 5 and the housing 2, and separate the housing 2 from the base 1 allowing a robot (not shown) to access the substrate 4.
When the low-pressure process apparatus 10 dries a photoresist material (for example, resin), volatile chemical or particles are deposited on an inner wall of the housing of the exhaust pipe 7. Thus, the housing 2 and the exhaust pipe 7 require regular cleaning. Conventionally, the housing 2 and the exhaust pipe 7 are manually cleaned after the housing is elevated. The cleaning process is difficult and time consuming. Additionally, when the housing 2 and the exhaust pipe 7 are cleaned, the low-pressure process apparatus 10 is shut down affecting process yield.